This is an incredibly important warning. I know people who have fucked things up with dd, and there's literally no going back. As someone mentioned below, people have put out massive rewards for finding a way to recover badly dd'd discs. Nobody has found a way.

Or install nwipe, the version that is actually kept up to date and doesn't require a special boot CD. The guy who wrote dban has started selling it as a full fledged product (more power to him), so others have taken up the open source alternative.

http://partedmagic.com/doku.php has a number of options, including a port of DBAN that can target one specific drive on a system and an implementation of "secure erase", which is a better way to go if your hard drive supports it.

The dd recipes work too. I consider one pass enough, unless you're worried about the NSA. (In that case, melt the drive down with a torch.)

Edit: secure-delete looks like a winXP program. You're asking how to use it in a FOSS subreddit